Add documentation to package

[fontikar]

A good R package will contain these 5 forms of documentation:

1. README which serves as a landing page for whoever finds your repo
2. Function/objection/package documentation e.g. ?mean()
3. Vignettes/Long form documentation serves as lengthier explainer of how to use your R package, usually a "Get Started" tutorial and other tutorials for more complex use cases
4. R package website

{rmot} already has the skeleton for 1-3
To learn more on how to create these : https://fontikar.github.io/DIY_Rpkg/#Document_it_-_Object_documentation_%E2%9C%85

I like to have a look at other packages and see how their write their documentation

For 4 check out: https://github.com/fontikar/DIY_Rpkg_pkgdown and https://fontikar.github.io/DIY_Rpkg_pkgdown/